Conventionally, there has been techniques to generate bird's-eye view images in an overlooking manner, respectively obtained by switching viewpoints of a plurality of camera images, and generate a synthesis bird's-eye view image by synthesizing the plurality of bird's-eye view images generated. In a bird's-eye view image generated by switching viewpoints, all the photographic objects in the image are displayed to exist in the same plane. Further, generally, since a bird's-eye view image is generated on the basis of the ground level, an object existing at a position above the ground is displayed to be distorted in an extended state as if the object fell down to the ground. Furthermore, when a synthesis bird's-eye view image is generated, generally, cameras are installed so that imaging ranges of adjacent camera images partially overlap with each other. An image of an object placed in an overlapping imaging range may disappear, or may be doubly seen due to influence of camera parallax.
Patent Literature 1 discloses a technique to preferentially display, as an image of an overlapping part, a bird's-eye view image wherein an image of a three-dimensional object appears to be larger out of two bird's-eye view images generated from two camera images whose imaging ranges partially overlap.